Journal of Minerals and Materials Characterization and Engineering, 2013, 1, 301-306
Published Online November 2013 (http://www.scirp.org/journal/jmmce)
Open Access JMMCE
The Effect o f M g O Dopant a n d L aser Treatment on ZnO
Fadhil A. Chyad1, Shaymaa Q. Abul Hassan2, Zyad T. Al-Dahan3
1Department of Materials Engineering, University of Technology, Baghdad, Iraq
2Department of Physics, College of Ibn-Al-Haithm, Baghdad University, Baghdad, Iraq
3College of Engineering, University of Al-Nahrian, Baghdad, Iraq
Received September 18, 2013; revised October 26, 2013; accepted November 6, 2013
Copyright © 2013 Fadhil A. Chyad et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ZnO ceramic samples as pellets have been prepared and doped with (1, 2.5, 5, 10 wt%) of MgO powder, sintering at
1300˚C, these samples have been treated with laser at 400 J/cm2. X-ray diffraction spectra of the samples show some
changes in the X-ray parameters, where d-spacing and the intensities of the peaks are changed. FWMH of all the sam-
ples was altered due to MgO dopant and the laser influence microstructure was affected by the laser treatment, also, the
texture coefficient is affected.
Keywords: ZnO; Laser Treatment; Texture Coefficient; FWMH; X-Ray Diffraction
Ceramic is an important class of materials which finds
increased applications as biomaterials, advanced structural
and engineering materials, where surface modifications
become important which were greatly influenced by the
surface microstructure defined by the morphology and
crystallographic texture of the surface grain .
ZnO is one of these ceramics with wide band gap
semiconductors which is used in optical devices near
It has good optical, electrical and piezoelectric proper-
ties because it has high transparence in the visible wave
length range and low electric resistance and its band gap
is 3.3 eV at room temperature .
It has been used in many applications such as gas sen-
sors, bulk acoustic wave devices, transparent conductive
oxide, solar cell windows besides its applications as
biomaterials against bacteria (i.e. solution or powders for
skin ointment). Many studies have been conducted on
laser interaction with ceramic materials, for example,
ceramics welding with laser have been studied by Ikeda
. For preventing crack for motion at the welded part, a
preheating at slow cooling was effective.
Mordike and Sivakumar  have used a laser beam to
locally melt and densify the ceramic coatings.
Harimkar and Dohotre  have discussed the micro-
structure development during surface modifications of
alumina ceramic using high power continuous wave
Krasnikov et al.  have been studied the effect of la-
ser treatment with varying pulse duration and pumping
voltage on ceramic material. They found the amorphaza-
tion of the ceramic structure in the laser beam action
zone is established.
Ural et al.  have studied the effect of laser treatment
on the bonding between zirconia ceramic surface and
resin cement which has a clear effect on the microstruc-
ture of bonding region.
Abeidia et al.  have studied the realization of molt-
ed layers with the CO2 laser on sintered alumina cera-
Dyshlovenko et al.  have used CO2 laser to treat
plasma sprayed hydroxylapatite coating. The laser beam
was scanned with speed of 6.4 mm/s. SEM and X-ray
diffraction enabled the determination of quantitative
Dimitrov et al.  have used pulsed laser deposition
which can provide crystallization at relatively low sub-
strate temperature due to the higher energy of the ablated
particles in the laser—produce plume and relatively high
Adawya et al.  have studied the deposition of
Al2O3 on glass substrate by PLD in 10−3 m bar oxygen
F. A. CHYAD ET AL.
ambient at different alumina concentration with laser
fluency energy 0.4 J/cm².
The aim of this work is to study the influence of Nd:
YAG laser on the microstructure and morphology of
ZnO ceramic with and without MgO.
2. Experimental Procedure
2.1. Materials Used
In the present study, ZnO powder used was obtained
from Fluka Company with 99.5% purity, and less than
25% µm particle size MgO obtained from Boh Company
with the purity 99.5%, and 25 µm particle size. PVA
(poly vinyl alcohol) is used as binder.
2.2. Equipments Used
1) Nd:YAG laser with 400 J/cm².
2) Digital balance (0.0001 gm) sensitivity.
3) Oven type cooper heat.
4) Hydraulic press type (BeGo) capacity 5 tons.
5) Electrical furnace (Ruhs Tral Co.) up to 1350˚C.
6) X-ray diffractions type (XRD 6000 SHIMADZU
JAPAN, λ = 1.5405A˚).
7) Optical microscope type (OLYMPUS OPTICAL
Co. LTD. JAPAN).
2.3. Samples Preparation
ZnO powder mixed thoroughly with 1.5% of PVA as a
binding material and pressed at 3 tons as a disc of 10 mm
diameter and 4mm thickness.
Other samples contain four percentages of MgO (1
wt%, 2.5 wt%, 5 wt% and 10 wt%) mixed and pressed as
the same above procedure.
All the samples dried at 80˚C in an oven for six hours
and then sintered in an electrical furnace at 1300˚C with
5˚C/min as a heating rate for 2 hrs and then cooling at the
same rate. All the samples have been treated with pulsed
3. Results and Discussion
3.1. Analysis of X-Ray Spectra
Laser surface modification of ZnO and ZnO doped MgO
ceramics with the range of laser influence (400 J/cm²)
employed in the present study.
X-ray diffraction patterns obtained at room tempera-
ture for ZnO sample before and after laser treatment are
shown in Figures 1 and 2.
After treatment, there was a change in the intensities
of the peaks with sharp altitude, also shift slightly to-
wards high 2
values which mean the d-spacing values
Figures 3-10 show the X-ray spectra of ZnO doped
Figure 1. XRD Spctrum of pure ZnO.
Figure 2. XRD Spctrum of treated ZnO by Laser.
Figure 3. XRD of ZnO doped with 1 wt% MgO sintered at
Figure 4. XRD Spectrum of ZnO 1 wt% MgO treated by
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F. A. CHYAD ET AL. 303
Figure 5. XRD Spectrum of ZnO 2.5 wt% MgO.
Figure 6. XRD Spectrum of treated ZnO 2.5 wt% MgO.
Figure 7. XRD Spectrum of ZnO 5 wt% MgO.
Figure 8. XRD Spectrum of treated ZnO 5 wt% MgO.
Figure 9. XRD Spectrum of ZnO 10 wt% MgO.
Figure 10. XRD Spectrum of ZnO 10 wt% MgO treated by
with different percentages of MgO (1 wt%, 2.5 wt%, 5
wt% and 10 wt%) before and after treatment by laser. At
1 wt% MgO dopant it is cleared that d-spacing is in-
creased by introducing the MgO oxide and the altitude of
peak intensities is increased again and the d-spacing val-
ues decreased at the laser treatment, but still higher than
those of pure ZnO as shown in Figure 4.
At 2.5 wt% MgO again sharp and high altitude of
peaks have shown with decreasing in d-spacing but after
treatment with laser the change in d-spacing values are
small with sharp peaks as shown in Figure 6.
Increasing the doping to 5 wt% MgO high peaks in-
tensities observed and the d-spacing values are decreased
sharply as shown in Figure 7. Figure 8 shows the spec-
tra of laser treatment of the samples have sharp peaks
and high intensities are observed with decreasing in d-
A small intensity peak at 2
equal 43.04 appeared in
this spectra which is belong to MgO according to N 1997
JCPAS No. 45-0946.
Figure 9 shows the spectra of 10 wt% MgO which has
very sharp peak with high intensity and high d-spacing
values , but at the treatment with laser the intensities are
decreased slightly with decreasing of d-spacing values , a
new peak with 2θ equal 42.63 which belong to MgO ob-
served with slight high intensity in Figure 10.
Open Access JMMCE
F. A. CHYAD ET AL.
In general, the analysis of X-ray spectra revealed a
systematic variation of relative intensities and d-spacing
values for all the spectra planes with MgO dopant and
3.2. Analysis of Texture Coefficient
Figure 11 shows the values of FWHM for all the sam-
ples which show that the addition of MgO is increased
the value of FWHM and the maximum is at 1 wt% and
then decreased, with treated the samples by laser the
value of pure ZnO is increased and the same behavior
with the doping of MgO.
The development of texture with the laser influence
can be quantified in terms of the texture coefficient (TC)
given by :
I hklI hkl
Tc hklIhkl nIhkl
where I(hkl) are measured intensities of (hkl) reflection,
Io(hkl) are powder reflection intensities of ZnO according
to ICDD PDF ≠ 36 - 1451 and (n)is the number of reflec-
tions used in the calculation.
Following (hkl) reflections corresponding (100,002,
101,102,110) of the samples the results of TC calculation
for (100) reflection are presented in Figure 12.
The figure indicates that the TC increased gradually
with increasing MgO content which reached maximum
value at 2.5 wt% and then decreased progressively; thus
substantiating the formation of strong (100) texture at the
intermediate MgO content, these two regimes of ex-
plored MgO contained less and greater than 2.5 wt%.
The variation of TCs and the relative intensity of (100)
plane corresponding closely with the regimes of MgO
content and laser influence which showed a distinct va-
riation in the morphology of surface grains in laser sur-
face modified ZnO ceramic as shown in Figure 12.
3.3. Analysis of Microstructures
The effect of laser irradiation on the surface microstruc-
ture of ZnO and ZnO doped MgO are illustrated in Fig-
ures 13-17. These figures present a set of optical surface
images which represent the untreated and treated samples
at laser influence of 400 J/cm².
The untreated samples consisted of irregular ZnO and
MgO grains with a degree of interconnected porosity.
It is evident that the surface microstructure of laser
modified ZnO ceramic is characterized by faceted po-
lygonal surface grains with varying size and the exten-
sion of surface faceting depend on MgO contend and
Some of the surface grains tend to deviate from po-
lygonal shapes transferred from irregular to near circular
Fi gure 11. Variation of (100) FWHM of untreated and treat-
ed samples with laser influences.
Conte nt ofMgO
Figure 12. Variation of (100) TC of untreated and treated
samples with laser influences.
Figure 13. Micrograph optical microscope of (a) untreated
and (b) laser treated of pure ZnO.
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F. A. CHYAD ET AL. 305
Figure 14. Micrograph optical microscope of (a) untreated
and (b) laser treated of ZnO with 1 wt% MgO.
Figure 15. Micrograph optical microscope of (a) untreated
Figure 16. Micrograph optiicroscope of (a) untreated cal m
and (b) laser treated of ZnO with 5 wt% MgO.
Figure 17. Micrograph optiicroscope of (a) untreated
and (b) laser treated of ZnO with 10 wt% MgO.
and (b) treated ZnO with 2.5 wt% MgO.
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F. A. CHYAD ET AL.
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